The percentage of CD3+CD4+ T cells, CD45+CD3+CD4+CXCR5+ T cells and CD4/CD8 ratio in peripheral blood of patients with ulcerative colitis and crohn’s disease was significantly lower than that of healthy controls, while the percentage of CD3+CD8+ T cells and CD19+CD5+ B cells in peripheral blood of patients with ulcerative colitis and crohn’s disease was significantly higher than that of healthy controls (Figures 2A, B). Here, CXCR5 is linked to Crohn disease.